Cotto have a weak chin??? What are you talking about, the way he fights, he barely raises his hands on defense. The guy fights like a mini foreman; pure ugly power shots. That's why I think he's the best pound for pound boxer. Maybe he's not anymore but the guy was on his way to beating the living crap out of Mayweather.
Knowing now that margarito cheated and going back to that fight, cotto was taking all of shots until the end. I like pacquiao but he is beatable and the soon to come Mayweather vs Pacquiao fight will show that.
But pound for pound, cotto before the Margarito fight was the best and he could have uncrowned Mayweather. Mind you that Margarito vs cotto fight was just a prep fight, so to speak, to Mayweather vs Cotto. Oscar had it all setup. Margarito basically stole probably one of the greatest fights that could have happened. Cotto vs Mayweather would have been legendary.